Chip Somodevilla/Getty Images(WASHINGTON) -- The FBI is "monitoring" the investigation into the death of an openly gay mayoral candidate in Mississippi, opening the door to a possible prosecution as a federal hate crime.

The FBI said in a statement that it "initiated contact" with Mississippi police on March 1 "to offer assistance."

"The FBI will continue its ongoing dialogue and sharing of information with the local and state agencies, and will continue to monitor this investigation for any indication that a potential violation of federal law exists," FBI spokeswoman Deborah Madden said in a statement.

Marco McMillian, 34, was found dead on Feb. 27. He was the Democratic candidate for mayor in the delta town of Clarksdale, Miss., and was considered one of the first viable openly gay candidates to run for office in the state. According to his family he was beaten, dragged from his car and burned after his death.

Lawrence Reed, 22, is the sole suspect and has been charged with murder.

State and local authorities are investigating the murder. Mississippi has a hate crime law that applies to victims of race-based crimes, but does not apply to sexual orientation.

Both McMillian and Reed are black.

On Tuesday, U.S. Rep. Bennie Thompson, a Democratic congressman whose district covers Clarksdale and who knew McMillian, called on federal authorities to investigate McMillian's death.

Cops found Reed in McMillian's car on Feb. 26, after he crashed the vehicle. McMillian, however, was nowhere to be found until the next day when his body was discovered.

Reed was taken to a nearby hospital in Tennessee. He was released on Sunday and remains in custody there, while awaiting extradition to Mississippi.

Police have not released a cause of death pending the results of a toxicology test, but McMillian's family said they were told he was severely beaten and burned after his death.

ABC News affiliate WPTY-TV on Tuesday reported that Reed contacted a family of sisters early on the morning of Feb. 26, prior to his car accident, in which he confessed to killing McMillian in self defense.

"He called at 12:11 a.m. and he told her that the dude [McMillian] was trying to rape him. He was exposing himself to him, playing with himself, telling him to do things and then he'll take him home," one family member, who was granted anonymity, told the station.

"He just looked like he had been through war..." another sister said. "He was standing in the back, back here, telling God to forgive him. He didn't mean to do it, and he was saying that he just wanted to die."

The sisters said they believed Reed was suicidal. "When he left out, he just drove out, sped up and hit a white truck head on."